Process for the production of nonwoven fabrics containing binders

ABSTRACT

THIS INVENTION RELATES TO A PROCESS FOR THE PRODUCTION OF NONWOVEN FABRICS CONTAINING BINDERS SUITABLE TO BE DYED BY REACTIVE DYES INCLUDING OPTICAL BRIGHTENERS WHICH COMPRISES IMPREGNATION OF THE NONWOVEN BY MEANS OF A BINDER PREPARATION CONTAINING IN ADDITION TO THE BINDER   (A) A POLYVINYL ALCOHOL, (B) REACTIVE CYCLIC METHYLOL COMPOUNDS, ALDEHYDES AND/OR COMPOUNDS YIELDING FORMALDEHYDE, (C) A METAL OR AMMONIUM SALT OF A STRONG MINERAL ACID, AND SUBSEQUENT DRYING AND CONDENSATION TREATMENT.

3,759,736 PROCESS FOR THE PRODUCTION OF NONWOVEN FABRICS CONTAINING BINDERS Hanns Jenny, Aarau, and Juerg Troesch, Allschwil, Switzerland, assignors to Sandoz Ltd. (also known as Sandoz AG), Basel, Switzerland No Drawing. Filed Mar. 9, 1971, Ser. No. 122,556 Claims priority, application Switzerland, Mar. 16, 1970, 3,8-58/ 70 Int. Cl. C08k N20 US. Cl. 117-335 T 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a process for the production of nonwoven fabrics containing binders suitable to be dyed by reactive dyes including optical brighteners which comprises impregnation of the nonwoven by means of a binder preparation containing in addition to the binder (a) a polyvinyl alcohol,

(b) reactive cyclic methylol compounds, aldehydes and/or compounds yielding formaldehyde,

(c) a metal or ammonium salt of a strong mineral acid, and subsequent drying and condensation treatment.

This invention relates to a process for the production of nonwoven fabrics containing binders suitable to be dyed by reactive dyes including optical brighteners which comprises impregnation of the nonwoven by means of a binder preparation containing in addition to the binder (a) a polyvinyl alcohol,

(b) reactive cyclic methylol compounds, aldehydes and/ or compounds yielding formaldehydes,

(c) a metal or ammonium salt of a strong mineral acid, and subsequent drying and condensation treatment.

Binders obtained by emulsion polymerization, e.g. in the presence of an emulsifier, are preferred, unless selfemulsifying polymers are selected.

The choice of binders depends on the properties which are to be imparted to the final nonwoven article, such as stiffness, flexibility, elasticity, tensile strength and heat stability. Depending on the end-use of the nonwoven fabrics, binders of any desired type, if preferred in the form of latices, can be used, for example polymers or copolyrners deriving from acrylic acid, acrylic acid derivatives (e.g. acrylic esters and/or acrylonitrile); butadiene; styrene; vinyl alcohol derivatives (e.g. vinyl acetate), e.g.

"United States Patent ice of lower acrylic or methacrylic acid alkyl esters, preferably those whose alkyl radicals contain 1 to 4 carbon atoms, and optionally acrylonitrile; butadiene, acrylonitrile and optionally methacrylic acid derivatives; butadiene, styrene and optionally acrylonitrile; or lower acrylic acid alkyl esters, styrene and acrylonitrile. It is preferable to use binders with a high content of acrylic acid derivatives. The binders as such are not or practically not suitable to be dyed by means of reactive dyestuffs.

Component (a) may be pure polyvinylalcohol or partly esterified by acetate groups (saponification degree between 5 and 100 preferably between and '90; the molecular weight ranging between 10,000 and 50,000 preferably between 15,000 and 20,000). Component (a) is employed preferably in the form of an aqueous solution.

Component (b) may be, for example, formaldehyde, or acetaldehyde or higher aldehydes. Examples of suitable compounds yielding formaldehyde are paraformaldehyde, trioxan and/or hexamethylene tetramine. Also dialdehydes such as glyoxal and glutaraldehyde may be successfully used.

As cyclic dimethylolurea derivatives may be used for example dimethylol ethyleneor dimethylolpropyleneurea, dihydroxyethyleneor dihydroxypropylene-dimethylol urea, methylol-melamine derivatives, compounds of formula o I! o where R represents lower alkyl or oxalkyl having e.g. 1 to 4 carbon atoms, or mixtures of the above mentioned compounds.

As compounds (c) which exercise the action of a catalyst, metal or ammonium salts of a strong mineral acid having a pH value below 7 in aqueous solution are used. The magnesium or zinc salts of a strong mineral acid such as hydrochloric or nitric acid are preferred; the first choice is magnesium chloride, the second zinc nitrate.

Any desired reactive dyes bearing at least one fibre-reactive radical can be employed as for instance dyes containing at least one halogenotriazine-, halogenoquinoxaline, halogenophthalazine ,S-oxyethylsulfonamidesulfonic ester or halogenopyridimidine radical.

As suitable reactive optical brighteners, those described in Swiss Pat. 353,243 may be cited, in particular those of formula OaH There is complete freedom as to the choice of fibrous materials for the formation of the nonwovens (cotton, regenerated cellulosic fibres, polyvinylchloride, polyester, polypropylene, polyacrylonitrile, polyamide, glass fibres etc.).

The process of this invention is especially noteworthy in that it is applicable with nonwovens of polyvinylchloride, polyester, polypropylene, polyacrylonitrile, and glass fibres since said fibres are not dyeable at all with reactive dyes.

For the production of the nonwovens containing binders according to this invention the nonwoven fabric is first impregnated under slightly acid to alkaline conditions, with the binder preparations containing the compounds and The compounds (a) and (b) are present in the impregnation liquor preferably in the ratio of 4:1 to 1:1 and more preferably 2:1. The liquor is preferably made alkaline with volatile alkali, for instance ammonia. The compound (c) acting as catalyst is present preferably in amounts of l-2% on the weight of the impregnating liquor.

A wetting agent can be optionally added to the impregnating liquor in order to improve the wettability of the non-woven.

The impregnating liquor can be applied by any suitable technique such as spraying, screen or foam impregnation, or by padding methods. It is best applied at low-temperatures, e.g. 5 C. to 50 C., the optimum range being 34 C. The impregnated nonwoven is dried by heating, e.g. at 70-120 C. which eliminates the volatile alkali until a slightly acid pH value is reached. The nonwoven fabric is then heat treated to condense the binder. The temperature range for this treatment is 130-200 C., optimally 150 C. and the time which is in inverse proportion to the temperature, is about 600 to 30 seconds (approximately 300 seconds at 150 C.). The temperature range is also conditioned by the nature of the fibre compositions. The bonded nonwoven can then be dyed, printed and/or optically brightened by one of the appropriate methods. For dyeings, an exhaust method can be employed on a padding technique such as the pad-steam, pad-batch, padroll or pad-thermosol processes. The nonwovens produced by the present process are also highly suitable for printing processes.

Another suitable technique is to apply reactive dye components or metallizable dyes and to aftertreat the nonwoven to form the final or metallized dye on the fibre.

The dyeings (the term dyeing comprising both dyeing and optical brightening) and prints thus produced are notable for very good light fastness, good rubbing fastness and very good fastness to wet treatments such as washing, water and perspiration.

In the following examples, which are illustrating but not limiting the invention, the parts and percentages are expressed by weight and the temperatures in degrees centigrade.

EXAMPLE 1 (a) Production of the nonwoven A liquor comprising:

50.0 parts of a binder preparation obtained by copolymerization of 36 parts of acrylic acid ethylester with 4 parts of acrylonitrile in the presence of 3 parts of the reaction product of 1 mole nonylphenyl with 12 moles ethylene oxide, 0.5 part of potassium persulphate and 0.2 part of sodium bisulphite in 56.3 parts of water;

0.3 part of ammonia (24% solution);

36 parts of a solution prepared by diluting with 48 parts of cold water, 24 parts of a 20% solution of a polyvinyl alcohol partly esterified by acetate groups (mol. weight 1520,000, saponification 75%);

parts of a mixture of ethyleneand propylene-dimethylolurea (50% solution);

4 1.8 parts of MgCl .6H O; 0.2 part of dioctyl sulphosuccinate (70% solution) and 9.2 parts of water.

The liquor has a pH of 8.0 to 8.5. Optionally said liquor is filtered through a sieve of fine mesh size prior to application. A nonwoven spunbounded polyester is impregnated at 25-30 with said liquor until increase of 180% over its dry weight.

The impregnated nonwoven is then dried at 110, and subsequently heated to 150 for 5 min. on which condensation takes plate.

(b) Dyeing example (thermosol process) 100 parts of the nonwoven produced above are padded at 2530 C. up to a increase in its weight with a liquor of the following composition:

15 parts of l-(2,5-dichlorophenyl) 3-methyl-4-(3"-trichloropyrimidylaminophenylazo)-5-pyrazolone 4',6- disulphonic acid in the form of the sodium salt parts of urea 20 parts of sodium carbonate (ash) 2 parts of sodium alginate 885 parts of water.

The treated nonwoven is dried at and thermofixed for 5 minutes at It is then rinsed first with cold and then with warm water (70%); rinsed at 80 with 5000 parts of an aqueous solution of 0.1% of a partially carboxymethylated alkylpolyglycolether and 0.25% sodium tripolyphosphate, rinsed again with water at 70 and dried. A nonwoven having a yellow shade is obtained which has very good light and wet rubbing fastness properties (wash ing at 60 and the severe water fastness test), together with good fastness to dry rubbing.

(c) Printing example A bonded nonwoven fabric produced as described in (a) is printed on a roller printing machine with an engraved design of 0.22 mm. depth with a paste of the following composition:

20 parts of the yellow dye of examples (b) 200 parts of urea 240 parts of water 450 parts of 4% sodium alginate thickening 30 parts of a 33 solution of the sodium salt of metanitrobenzenesulphonic acid 60 parts of a 25% sodium carbonate solution.

After drying, the print is thermofixed for 5 minutes at The nonwoven is then rinsed cold with overflow and washed in two consecutive baths, each consisting of an aqueous solution of 0.1% of a partially carboxymethylated alkylpolyglycol ether and 0.25 sodium tripolyphosphate, at 80 and liquor ratio 50:1, the first time for 1 minute and the second time for 5 minutes. Finally it is rinsed at 70 and dried.

A yellow print is obtained on the nonwoven by this procedure which has very good light and wet rubbing fastness properties (washing at 60 and the severe water test), with good dry rubbing fastness.

The following Table 1 gives details of further examples of dyeings and prints obtainable by the procedures of Examples 1(b) and (c) respectively. They are distinguished by the shade of the dyeing or print on a nonwoven produced in accordance with Example 1(a).

TABLE 1 Dyeing proce- Printing proce- Shade of dying and dure as in dure as in print on the Example No. Dye, sodium salt oi- Example 1(b) Example 1(0) nonwoven 2 2-(4-trichloropyrimidylaminophenylazo)naphthalene-4,6,8-trlsulphonic aeid Reddish yellow. 3 1:2 cobalt complex of 1-(2-hydroxy-5-nitrophenylazo)-2-hydroxy-3-trichloro- Reddish brown.

pyrimidylaminonaphthalene-7,3-disulphonic acid. 4 l-hydroxy-2-(3-trichloropyiimidylamindphenylazo)-naphthalene-4,6,6- Scarlet.

tri sulphonic acid. 5 l-hyfirloxyflphenglazo-8-t1ichloropyrimidylaminonaphthalene-E,5,6'-tri- Red.

su p omc aci l-hydroxy-2-phenylazo'8 trichloropyrlmidylaminonaphthalene-3,6,6- Bluish red.

trisulphonic acid. 1:1 copper complex of 1-hydr0xy-2-(2-hydroxyphenylazo)-8-trichloropyrimidyl- Reddish violet.

amino-naphthalene-3,6,5-trisulphonic acid. 1-amino4-(3-trichloropyrimidylaminophenylamino)-anthraquinone-2,4',6- Reddish blue.

trisulphonic acid. 9 Copper htha1ocyanine-(3,3 ,3 ,3 ")-Sulphonic aeid-disulphonamide-sulphonic Turquoise.

acid 3-trichloropyrimidylaminophenylamide). 10 1:1 copper complex of 1-hydroxy-2-(2-hydroxy-5-trichloropyrimidylamino- Reddish navy blue.

phenylazo)-8-aminonaphthalene-5,7 ,3-t1isulpl1onic acid. 11 1:2 chromium complex of l-hydroxy-2-(2'41ydroxy-5-chlorophenylazo)-8- Navy blue.

trichloropyrimidylaminonaphthalene 3,6disulphonic acid. 12 1:2 chromium complex of l-hydroxy-2-(2-hydroxy-5-nitrophenylazo)-8- Bluish grey.

trichloropyrimidylaminonaphthalenefi,fi-disulphonic acid. 13 1:2 mixed chromium-cobalt complex of l-hydroxy-Z-(2-hydroxy-5-nitro- Black.

phenylazo)-8-trichloropyrimidylaminophthalene-3,6-disulphonic acid. 14 1:2 mixed chromium-cobalt complex of the sodium salt of 1-hydroxy2-(2- Blue,

hydroxy-(Y-nitronaphthyl-l-azo)-6- (4-chloro-6"-amino-l ,3,5-triazinyl- 2-amino)-naphthalene-3,4disulionic acid. 15 The sodium salt Lamina-i(3'-t1ichlorpyrimidylamino-phenylamino)-anthra- Do.

quinonc-2,4-6-trisulphonic acid. 16 Disodium salt of copperphthalocyanine-(3)-disulphomc-sulphonamid-sul- Turquoise bin phonic acid-(3-tn'chloropyrimidylamino)-phenylamid. 17 Reacton navy blue ZRL (0.1. 10S 51 Navy blue. 18 Solidazol pink brilliant RL (0.1. 69 A e- A 403)- Brilliant pink. 19 Solidazol blue brilliant (0.1. 53 A e- A 403) Brilliant blue.

EXAMPLE 20 (a) A nonwoven of polypropylene fibre is impregnated as described in Example 1 with a liquor of the following composition:

50 parts of an aqueous, anionically stabilized dispersion of Acronal 500D (an acrylic butylester-vinyl acetate copolymer with a dry content of approximately 45%) 36 parts of a solution prepared by diluting 24 parts of 20% solution of a polyvinylalcohol containing acetate groups (molecular weight 4050,000, saponification depolyethylene sheeting to exclude air. For fixation of the dye the roll is stored for 24 hours at room temperature, preferably with rotation. After treatment is carried out as in Example 1. A yellow dyeing is obtained on the nonwoven which has very good fastness to light, wet rubbing fastness (Washing at and the: severe Water fastness test) and dry rubbing fastness.

The following table lists further examples of dyeings which are obtainable by the procedure of Example 20(b); they are distinguished by the dye used and the shade of the dyeing on a nonwoven produced as given in Examgree 98%) 40 ple 20(a),

TABLE 2 Shade of Dyeing procdyeing and ess as in print on Example the non- Example y 200a) woven 21 Sodium-l-Z,5-d.ichloropheny1)-3-methyl1-[3"-(4,6"-dichl0ro1"',3,5-triazinyl-2-arnino)- Y ll pheny1azo1-5pyrazo1one4,6-disulphonate. 'I 22..-; Sodium-1-hydroxy-2- enylazo-6-(4,6"-dioh1oro-1,3",5-tnazinyl-2 -amino)-naphthalene-3,2-d1sulph0nate- Orange. 23- Levafix Red E-2G (81. 89 A e- A 664).. 3 21... Levafix Yellow E-RL (0.1. 26 A e- A 101) Y ll w 25--. Reactofil Blue (0.1. 83 A e- A 702) a Blue 26--- Reactofil Brillant Red GL (0.1. 91 A e- A 701) 3 27 Copper complex compound of potassium-l-hydroxy-2-(2-hydroxy -vmylsulphonylphenylazo)-8- V 1 acetylaminonaphthalene-3,6-disulphonate. 28 Potassium-l-(2-chloro-6'-methylphenyl)-3-methyl-4-(2"-meth0xy-5"'sl1lphat0-ethylsuli'onylphenylazo)-5- Yellow pyrazolone-4-sulphonate.

2.5 parts of 1:1 mixture of a dihydroxyethylene dimeth- EXAMPLE 29 ylolurea and a melamine-formaldehyde resin 1.8 parts of ammonium sulphate 0.2 part of dioctyl sulphosuccinate and 9.5 parts of water.

impregnation is followed by drying and condensation.

(b) Dyeing Example (pad-batch process) 100 parts of the bonded nonwoven produced as given in the foregoing are padded at 25-30 up to a 90% increase in weight with a liquor of the following composition:

15 parts of sodium 1-(2,5-dichlorophenyl)-3-methyl-4- [3 (4',6' dichloro l',3,5" triazinyl-2"- amino -phenylazo] -5-py razolone-4'-, 6"-disulphonate 25 parts of soda ash and 960 parts of water.

The nonwoven is rolled up and the roll wrapped in (a) A carded nonwoven of regenerated cellulosic and polyamide fibres (:25) is impregnated in accordance with the procedure of Example 1 with a liquor of the following composition:

' Impregnation is followed by drying and condensation.

(b) Dyeing example (pad-roll process) 100 parts of the carded nonwoven, bonded as described above, are padded at 2530 up to a 90% increase in weight with a liquor ratio of the following composition:

20 parts of sodium 1-amino-4-(3-trichloropyrimidilaminophenylamino)-anthraquinone-2,4-6'-trisulphonate parts of sodium hydroxide solution of 36 B.

10 parts of soda ash 80 parts of Glaubers salt and 885 parts of water.

After padding, the nonwoven is heated up to 70 and rolled up. For fixation of the dye it is stored in the enclosed chamber of the pad-roll range for 3 hours at a wet bulb temperature of 70 and a dry bulb temperature of 75. Subsequently it is aftertreated as described in Example 1. A blue dyeing is obtained on the nonwoven which has very good fastness to light, wet rubbing fastness (washing at 60 and the severe water test) and dry rubbing fastness.

In place of the aforementioned dye, any other of the dyes listed in Table 1 can be used with the same good results.

EXAMPLE 30 (a) A carded nonwoven of polyamide and polyacrylonitrile fibres (80:20) is impregnated as disclosed in Example 1 with the following liquor:

50 parts of synthorner 3500 (an anionically stabilized copolymer containing carboxylic groups based on butadiene-styrene; approximate dry content 45) 2.5 parts of a 1:1 mixture of glyoxal and propylene dimethylolurea 1.8 parts of ammonia nitrate 0.2 part of dioctyl sulphosuccinate and 9.5 parts of water.

Impregnation is followed by drying and condensation.

(b) Dyeing example (one-bath steam process) 100 parts of the nonwoven produced as described above are padded at 25-30" up to a 90% increase in weight with a liquor of the following composition:

parts of copperphthalocyanine (3)-disulphonic acidsulphonamide sulphonic acid 3 trichloropyrimidylamino-phenylamide in the form of the sodium salt 100 parts of urea parts of soda ash 2 parts of sodium alginate 5 parts of a 33% solution of the sodium salt of m-nitrobenzenesulphonic acid and 858 parts of water.

The padded nonwoven is dried in a hot flue and the dyeing fixed by treatment for 15 minutes in saturated steam. It is aftertreated as in Example 1. The procedure results in a blue dyeing showing good fastness to light, wet rubbing fastness (washing at 60 and the severe water test) and dry rubbing fastness.

In place of the aforementioned dye any of the other dyes listed in Tables 1 and 2 can be employed with the same good results.

(c) Dyeing examples (pad-steam process) 100 parts of a nonwoven produced as in Example are impregnated at 2530 up to a 90% increase in weight with a liquor of the following composition:

15 parts of sodium 1 amino-4-(3-trichloro-pyrimidilaminophenylamino) anthraquinone 2,4',6 trisulphonate 2 parts of sodium alginate and 983 parts of water.

After intermediate drying on a hot flue the nonwoven is padded once more, again at 2530 and up to a 90% in weight increase with the following liquor:

250 parts of Glaubers salt 20 parts of sodium hydroxide 5 parts of sodium m-nitrobenzenesulphonate and 725 parts of water.

The moist nonwoven is steamed for 1 minute at with saturated steam and aftertreated as in Example 1. A blue dyeing is obtained on the nonwoven which has good fastness to light, wet rubbing fastness (washing at 60 and the severe water test) and dry rubbing fastness.

In place of the aforementioned dye any of the other dyes listed in Tables 1 and 2 can be used with the same good results.

Example 31 A nonwoven produced as described in Example 25 is entered into an exhaust dyebath at room temperature and at a liquor to goods ratio of 10:1. The bath is raised in 30 minutes to the temperature given in Table 3 for the dye bath. During the heating-up period, Glaubers salt is added in three portions after 10, 20 and 30 minutes. When the respective dyeing temperature is reached, sodium carbonate is added and dyeing continued for 60 minutes for fixation. The nonwoven is rinsed and soaped as given in Example 1.

The composition of the dyebath is as follows:

5 parts of one of the dyes listed in Table 3 60 parts of Glaubers salt 15 parts of soda ash 2 parts of sodium m-nitrobenzenesulphonate and 920 parts of water.

Shade of dyeing Having thus disclosed the invention what we claim is:

1. In a process wherein a nonwoven fabric is impregnated with a binder preparation, the improvement, whereby said nonwoven fabric is rendered suitable for dyeing and optical brightening with fiber reactive dyestuffs and optical brighteners, which comprises incorporating in the binder preparation, in addition to the binder (a) a polyvinyl alcohol (b) a member of the group consisting of reactive cyclic methylol compounds, aldehydes, compound yielding formaldehyde and mixtures thereof, and

(c) a metal or ammonium salt of a strong mineral acid,

the weight ratio of said component (a) to said component (b) being in the range 4:1 to 1:1, and subsequently drying said binder preparation and condensing under acid conditions.

2. A process of claim 1 wherein the nonwoven fabric is impregnated under slightly acid to alkaline conditions, the pH is then adjusted to slightly acid and the condensation is effected at a temperature of 100 to 200 C.

3. A process according to claim 2 wherein the compounds (a) and (b) are employed in a weight ratio of 2: 1.

4. A process according to claim 2 wherein the impregnation is effected under alkaline conditions and the condensation is effected at temperatures in the range of to C.

5. A process according to claim 2 wherein the binder preparation contains a volatile alkali when applied to the fabric and the alkali is volatilized by heat to render the binder preparation acidic for condensation.

6. A process according to claim 2 wherein the binder preparation is rendered alkaline with ammonia, applied to the nonwoven fabric at a temperature of 5 to C., heated to to C. until an acid pH is reached and then at to C. to eifect condensation.

7. A process according to claim 2 which includes the step of dyeing or optically brightening the nonwoven fabric with a reactive dye or a reactive optical brightener following condensation of the binder preparation.

8. A process according to claim 7 wherein the nonwoven fabric is treated with the dye components or op-- tical brightener components and the components are then converted into reactive dyes or optical brighteners.

10 References Cited UNITED STATES PATENTS 3,326,740 6/1967 'Hand 61; a1. 2s -73 x 2,341,735 2/1944 Monsoraflt' 28--73 X 5 2,898,239 8/1959 Sulzer et al. s- 1 R x 3,232,691 2/1966 Wilhelm a a1. 117-335 T x ALFRED L. LEAVITT, Primary Examiner 10 C. WESTON, Assistant Examiner US. Cl. X.R.

8-1 W; 28-74 R; 117-1395 R 

